A New Control Architecture for Robust Controllers in Rear Electric Traction Passenger HEVs

It is well known that control systems are the core of electronic differential systems (EDSs) in electric vehicles (EVs)/hybrid HEVs (HEVs). However, conventional closed-loop control architectures do not completely match the needed ability to reject noises/disturbances, especially regarding the input acceleration signal incoming from the driver's commands, which makes the EDS (in this case) ineffective. Due to this, in this paper, a novel EDS control architecture is proposed to offer a new approach for the traction system that can be used with a great variety of controllers (e. g., classic, artificial intelligence (AI)-based, and modern/robust theory). In addition to this, a modified proportional-integral derivative (PID) controller, an AI-based neuro-fuzzy controller, and a robust optimal H-infinity controller were designed and evaluated to observe and evaluate the versatility of the novel architecture. Kinematic and dynamic models of the vehicle are briefly introduced. Then, simulated and experimental results were presented and discussed. A Hybrid Electric Vehicle in Low Scale (HELVIS)-Sim simulation environment was employed to the preliminary analysis of the proposed EDS architecture. Later, the EDS itself was embedded in a dSpace 1103 high-performance interface board so that real-time control of the rear wheels of the HELVIS platform was successfully achieved.

A new aspect of sign and its implications for the Theory of Communication

Este artigo propõe que a semiótica peirceana pode oferecer bases tanto lógicas quanto epistemológicas para a busca de uma teoria geral da comunicação. No entanto, o desenvolvimento de uma teoria semiótica da comunicação depende, em primeiro lugar, de uma melhor compreensão dos aspectos formais do signo, tarefa atribuída por Peirce à gramática, o primeiro ramo de sua semiótica. Nós apresentamos uma análise das relações do signo, revelando um aspecto não trabalhado por Peirce, ampliando seu número para onze. Este novo aspecto é a relação triádica entre signo, objeto dinâmico e interpretante dinâmico (S-OD-ID). Nós defendemos que esta relação é essencial para a compreensão da comunicação como semiose, por dar conta da repetição ou redundância do signo comunicativo, quando se cria ou transmite informação. O artigo pretende dar um passo a mais na direção de uma teoria da comunicação verdadeiramente universal, através do vínculo entre a semiótica peirceana e a moderna filosofia da linguagem.

QUANTUM FIELD THEORY IN GRAPHENE

This is a short nontechnical introduction to applications of the Quantum Field Theory methods to graphene. We derive the Dirac model from the tight binding model and describe calculations of the polarization operator (conductivity). Later on, we use this quantity to describe the Quantum Hall Effect, light absorption by graphene, the Faraday effect, and the Casimir interaction.

Electrostatic potentials and polarization effects in proton-molecule interactions by means of multipoles from the quantum theory of atoms in molecules

Some atomic multipoles (charges, dipoles and quadrupoles) from the Quantum Theory of Atoms in Molecules (QTAIM) and CHELPG charges are used to investigate interactions between a proton and a molecule (F2, Cl2, BF, AlF, BeO, MgO, LiH, H2CO, NH3, PH3, BF3, and CO2). Calculations were done at the B3LYP/6-311G(3d,3p) level. The main aspect of this work is the investigation of polarization effects over electrostatic potentials and atomic multipoles along a medium to long range of interaction distances. Large electronic charge fluxes and polarization changes are induced by a proton mainly when this positive particle approaches the least electronegative atom of diatomic heteronuclear molecules. The search for simple equations to describe polarization on electrostatic potentials from QTAIM quantities resulted in linear relations with r-4 (r is the interaction distance) for many cases. Moreover, the contribution from atomic dipoles to these potentials is usually the most affected contribution by polarization what reinforces the need for these dipoles to a minimal description of purely electrostatic interactions. Finally, CHELPG charges provide a description of polarization effects on electrostatic potentials that is in disagreement with physical arguments for certain of these molecules. (c) 2012 Wiley Periodicals, Inc.

Interactions between 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and gamma-Al2O3 (100) surface calculated by density functional theory

The main aim of this work is to investigate the 1-butyl-3-methylimidazolium tetrafluoroborate ([C4C1Im]+[BF4]-) ionic liquid (IL) adsorption on the gamma-Al2O3 (100) by density functional theory calculations to try to rationalize the adsorption as an electrostatic phenomenon. Optimized geometries and interaction energies of IL one-monolayer on the gamma-Al2O3 were obtained on high surface coverage (one cationanion pair per 94.96 nm2). A study of dispersion force was made to estimate its contribution to the adsorption. Overall, the process is ruled by electrostatic interaction between ions and surface. Adsorption of the anion [BF4]- and cation [C4C1Im]+ was also studied by Bader charge analysis and charge density difference for supported and unsupported situations. It is suggested that the IL ions have their charges maintained with significant anion cloud polarization inward to the acid aluminum sites. (c) 2012 Wiley Periodicals, Inc.

Resonances in Mie scattering by an inhomogeneous atomic cloud

Despite the quantum nature of the process, collective scattering by dense cold samples of two-level atoms can be interpreted classically describing the sample as a macroscopic object with a complex refractive index. We demonstrate that resonances in Mie theory can be easily observable in the cooperative scattering by tuning the frequency of the incident laser field or the atomic number. The solution of the scattering problem is obtained for spherical atomic clouds who have the parabolic density characteristic of BECs, and the cooperative radiation pressure force calculated exhibits resonances in the cloud displacement for dense clouds. At odds with uniform clouds which show a complex structure including narrow peaks, these densities show resonances, yet only under the form of quite regular and contrasted oscillations. Copyright (C) EPLA, 2012

Platinum-Based Nanoalloys PtnTM55-n (TM=Co, Rh, Au): A Density Functional Theory Investigation

Structural and electronic properties of the PtnTM55-n (TM = Co, Rh, Au) nanoalloys are investigated using density functional theory within the generalized gradient approximation and employing the all-electron projected augmented wave method. For TM = Co and Rh, the excess energy, which measures the relative energy stability of the nanoalloys, is negative for all Pt compositions. We found that the excess energy has similar values for a wide range of Pt compositions, i.e., n = 20-42 and n = 28-42 for Co and Rh, respectively, with the core shell icosahedron-like configuration (n = 42) being slightly more stable for both Co and Rh systems because of the larger release of the strain energy due to the smaller atomic size of the Co and Rh atoms. For TM = Au, the excess energy is positive for all compositions, except for n = 13, which is energetically favorable due to the formation of the core-shell structure (Pt in the core and Au atoms at the surface). Thus, our calculations confirm that the formation of core-shell structures plays an important role to increase the stability of nanoalloys. The center of gravity of the occupied d-states changes almost linearly as a function of the Pt composition, and hence, based on the d-band model, the magnitude of the adsorption energy of an adsorbate can be tuned by changing the Pt composition. The magnetic moments of PtnCo55-n decrease almost linearly as a function of the Pt composition; however, the same does not hold for PtRh and PtAu. We found an enhancement of the magnetic moments of PtRh by a few times by increasing Pt composition, which we explain by the compression effects induced by the large size of the Pt atoms compared with the Rh atoms.